1. Field
The embodiments discussed herein are directed to a wiring design method.
2. Description of the Related Art
Generally, a semiconductor integrated circuit (LSI) and a large-scale printed circuit board are wired by an automatic wiring technique. In recent years, the number of cells including in a semiconductor integrated circuit, and the number of components mounted on a printed circuit board have been significantly increased. Before the automatic wiring of a semiconductor integrated circuit or a large-scale printed circuit board is performed, a wiring region in which wirings are arranged is divided into a plurality of small regions (here, called “G-cells”) according to a fixed rule. When the wiring region is divided into G-cells, a wiring route of each net may be set by determining the G-cells passed by a wiring and determining the order in which the G-cells are passed by the wiring.
The amount of wirings which can be accommodated in each G-cell is limited. Therefore, the wiring resource of each G-cell represents the amount of wirings which can be accommodated in each G-cell. The wiring resource is, for example, the number of wirings or the number of grid points. Wiring routes are assigned to each G-cell within a range not to exceed the wiring resource.
The grid point may be defined as a point used as a base unit of wiring. The grid point means an intersection of lines arranged with a predetermined pitch interval in two directions orthogonal to each other. A wiring route is determined as a combination of lines each of which is formed by connecting between the grid points adjacent to each other in parallel with one of the two directions. The number of wirings calculated as the wiring resource is, for example, the number of straight lines (wiring tracks) which are calculated for each of the two directions and which can be assigned as wiring routes to across the entire G-cell.